"Please call Stella. Ask her to bring these things with her from the store: six spoons of fresh snow peas, five thick slabs of blue cheese, and maybe a snack for her brother Bob. We also need a small plastic snake and a big toy frog for the kids. She can scoop these things into three red bags, and we will go meet her Wednesday at the train station."

You can hear these words recited 1,300 times at the online speech accent archive at George Mason University in Fairfax, Virginia – and every one is different.

The archive was set up to exhibit "a large set of speech accents from a variety of language backgrounds". Native and non-native English speakers are recorded – or record themselves – reading the passage, chosen because it contains most of the consonants, vowels and clusters of Standard American English. These recordings make up the archive.

Steven H Weinberger, associate professor and director of linguistics at the university, is the administrator of the archive, which has been on the web since 1999. Anyone can submit a sample. "We get them all of the time, from people all over the globe," he says. "We simply ask for CD-quality recordings, and we get some very good recordings. We also get noisy, badly recorded ones, which we discard. If the recording is good, and the data are confirmed, we accept it and add it to the archive."

Contributors answer questions about their demographic and linguistic background to enable archive users "to determine which variables are key predictors of each accent". If you are, say, a 56-year-old male native English speaker from the north of England and the archive already has a sample matching that background, you will not be rejected.

"All speakers are slightly different from each other, and that is interesting in itself," says Weinberger. "If we have 75 Spanish speakers, there are a number of different countries represented. The same goes for Arabic.

"There are loads of gaps, mainly in the less common languages like those spoken on small islands (Tahitian, Balangingi, etc) or Native American languages and ASL (American Sign Language)."

Does he have any favourites? "I like all of them, but I find the older speakers most instructive. Many of our speakers who are older than 70 seem to have the most 'archetypal' accents."

You can search the online archive by language or geography, or just enjoy a browse; alongside each recording is a phonetic transcription. So, for example, you can compare the accent of a female native Afrikaans speaker aged 27, who learned to speak English at nine, with a 43-year-old man, from a different region of South Africa, who learned English at four; or you can hear accents of native Arabic speakers from Egypt, Israel, Iraq, Saudi Arabia or Syria.

There is something almost hypnotic about the repeated recitation of the passage. The irony is that hearing the same words over and over, in the same language, nonetheless says something powerful about how much people have in common despite their differences – it's like the Tower of Babel in reverse.

Crucial to an understanding of accents is that they are "systematic rather than merely mistaken speech", Weinberger says. This can counter what he describes as "biased social judgments" based on people's accents. "When we understand that accents are not due to 'errors' or faulty learning, we may be more sympathetic to the speakers. But biases are hard to unlearn."

So how and when do we acquire our accent? "As human listeners, we have a fairly automatic ability to listen to a snippet of speech and instantaneously determine whether or not that speaker is from our community: five-year-olds can do this.

"When it comes to foreign (non-native) speakers, there seems to be something that all French speakers share, all Mandarin Chinese speakers share, etc. The French speakers of English are substituting, altering, deleting and adding sounds to their English making it different from that of a native English speaker. When we distill what they do to their English, we see patterns: French speakers sound French because they are using French sounds and structures in their English.

"It is not willy-nilly, but systematic. Most French speakers of English can be shown to do these specific (French) things, Swahili speakers to do Swahili things, and so on. So what we 'hear' in an accent is really the system of grammar from the talker's native language. Studying accents is just like studying native sound systems. But don't get me wrong," he adds. "There are still lots of other things about accents that may be more ideosyncratic.

"Everyone has an accent, and we are biologically wired to have an accent. Most linguists believe that there is a 'critical period' for humans when they can acquire a language perfectly. After this age has passed (around six years old) humans will learn a language incompletely — and this shows up most often in the pronunciation.

"The archive generally confirms this notion of a critical period. It is only the very young learners who manage to pass for native speakers of English. So a person – let's say Korean – who starts learning English at age 11, and lives in the USA for 20 years speaking English, will still have a Korean accent. But a Korean who starts her English at four, and moves to the USA and lives there for five years, will not have a Korean accent. So it is age of onset, not length of exposure, that is crucial."

The archive is used for teaching and research. As well as linguists and phoneticians, groups who use it range from teachers of English as a foreign language, and engineers training speech recognition machines, to speech pathologists and actors who need to learn an accent. Does Weinberger ever get sick of hearing about fresh snow peas and slabs of blue cheese? "Sure, and so do my family and students. But some people like it – just Google 'please call Stella ...' You will find that people have used it for all sorts of projects." There are ringtones and art projects, you can find it on YouTube, and the Irish composer Cathal Roche has written saxophone pieces based on the archive.

"There have been academic papers and masters' theses based upon the data too, but I think most people just like to listen to accented speech. I am sure there are plenty of drinking games based on the archive!"

Actors' accents

Had the archive been around at the time, we might have been spared the vocal grotesqueries of actors such as Van Dyke and Sean Connery – who topped Empire magazine's poll of the worst accents in cinema history for their work on, respectively, Mary Poppins (1964) and The Untouchables (1987). "We get mail of thanks from many actors who are working with scripts that require obscure speech accents," Weinberger says.

So what next? "We are getting ready for another major overhaul: better maps via Google, more searchable sounds, and more phonetic inventories from the world's languages. We are also putting together a database of the syllable structures available in the world's languages.

"We have also made a computational device that will automatically compare two accents. It will instantaneously reveal the specific phonological speech patterns that make one accent different from another. It's exciting work, and it will be available, free, to anyone."

In the meantime, he carries a voice recorder with him all the time – "I never know when I will encounter an interesting accent." Will the archive ever be regarded as complete? "We don't have an end date. We only have about 300 native languages represented. With 6,000 world languages out there, we have a long way to go."